Heretofore it has been customary to use, as an electronic component housing package for mounting an electronic component such as a piezoelectric oscillation device or a semiconductor device, a construction comprising an insulating substrate made of, for example, ceramic sintered body, which has a mounting section for receiving an electronic component. A lid body is joined to an upper surface of the insulating substrate so as to cover the mounting section. Such an electronic component housing package is basically composed of: an insulating substrate comprising a flat plate-shaped base having an electronic component mounting section at its upper surface, and a frame in the form of a frame laminated on an upper surface of the base so as to surround the mounting section; and wiring conductors formed in the range from the mounting section to a lower surface of the base and so forth.
Of the wiring conductors, one disposed in the mounting section functions as a connection conductor to which an electronic component is connected, whereas one disposed on the lower surface of the base (a lower surface of the insulating substrate) functions as a conductor for external connection (external connection conductor). An electronic apparatus is produced by mounting an electronic component in the mounting section while providing electrical connection between the connection conductor and each electrode of the electronic component, and thereafter sealing the mounting section with a lid body, for example. Moreover, an upper surface of the frame is provided with a frame-shaped metallized layer for the joining of a metal-made lid body. In this electronic component housing package, the lid body is joined to the frame-shaped metallized layer via a sealing material such as silver solder, thus hermetically sealing the electronic component in the mounting section.
There may be a case where the frame-shaped metallized layer and the lid body stand at the same potential as ground potential to obtain a structure in which an inside of the mounting section in which the electronic component is mounted is shielded from external noise. A method for obtaining such a structure involves, for example, placement of a side-surface conductor on the inner side surface of the frame, placement of a relay conductor connected to the external connection conductor set at the ground potential on the mounting section, and establishment of connection between the frame-shaped metallized layer and the external connection conductor set at the ground potential via the side-surface conductor or the relay conductor, for example (refer to Japanese Unexamined Patent Publication JP-A 2000-312060).